Melatonin receptor

Melatonin receptor

melatonin receptor 1A
Identifiers
Symbol MTNR1A
Entrez 4543
HUGO 7463
OMIM 600665
RefSeq NM_005958
UniProt P48039
Other data
Locus Chr. 4 q35.1
melatonin receptor 1B
Identifiers
Symbol MTNR1B
Entrez 4544
HUGO 7464
OMIM 600804
RefSeq NM_005959
UniProt P49286
Other data
Locus Chr. 11 q21-q22

A melatonin receptor is a G protein-coupled receptor (GPCR) which binds melatonin.[1]

Three types of melatonin receptor have been cloned. The MT1 (or Mel1A or MTNR1A) and MT2 (or Mel1B or MTNR1B) receptor subtypes are present in humans and other mammals,[2] while an additional melatonin receptor subtype MT3 (or Mel1C or MTNR1C) has been identified in amphibia and birds.[3]

Expression patterns

In mammals, melatonin receptors are found in the [4]

MT1

In humans, The MT1 subtype is expressed in the pars tuberalis of the pituitary gland and the suprachiasmatic nuclei of the hypothalamus.

MT2

The MT2 subtype is expressed in the retina. MT2 receptor mRNA has not been detected by in situ hybridization in the rat suprachiasmatic nucleo or pars tubealis.[5]

MT3

The MT3 subtype of many non-mammalian vertebrates is expressed in various brain areas.[3]

MT Receptor function

MT1

In humans, The MT1 subtype's expression in the pars tuberalis of the pituitary gland and suprachiamatic nuclei of the hypothalamus is indicative of melatonin's circadian and reproductive functional involvement.

MT2

In humans, the MT2 subtype's expression in the retina is suggestive of melatonin's effect on the mammalian retina occurring through this receptor. Research suggests that melatonin acts to inhibit the Ca2+-dependent release of dopamine.[5] Melatonin's action in the retina is believed to affect several light-dependent functions, including phagocytosis and photopigment disc shedding.[6]

MT3

Selective Ligands

Agonists

Antagonists

See also

References

  1. ^ Reppert SM (1997). "Melatonin receptors: molecular biology of a new family of G protein-coupled receptors". J. Biol. Rhythms 12 (6): 528–31.  
  2. ^ Reppert SM, Weaver DR, Godson C (1996). "Melatonin receptors step into the light: cloning and classification of subtypes". Trends Pharmacol. Sci. 17 (3): 100–2.  
  3. ^ a b Sugden D, Davidson K, Hough KA, Teh MT (2004). "Melatonin, melatonin receptors and melanophores: a moving story". Pigment Cell Res. 17 (5): 454–60.  
  4. ^ Morgan PJ, Barrett P, Howell HE, Helliwell R (1994). "Melatonin receptors: localization, molecular pharmacology and physiological significance". Neurochem. Int. 24 (2): 101–46.  
  5. ^ a b Reppert SM, Godson C, Mahle CD, Weaver DR, Slaugenhaupt SA, Gusella JF (September 1995). "Molecular characterization of a second melatonin receptor expressed in human retina and brain: the Mel1b melatonin receptor". Proc. Natl. Acad. Sci. U.S.A. 92 (19): 8734–8.  
  6. ^ Besharse JC, Dunis DA (March 1983). "Methoxyindoles and photoreceptor metabolism: activation of rod shedding". Science 219 (4590): 1341–3.  
  7. ^ Nickelsen T, Samel A, Vejvoda M, Wenzel J, Smith B, Gerzer R (September 2002). "Chronobiotic effects of the melatonin agonist LY 156735 following a simulated 9h time shift: results of a placebo-controlled trial". Chronobiol. Int. 19 (5): 915–36.  

External links